feat: add relationships to ELF package discovery (#2715)

This PR adds DependencyOf relationships when ELF packages have been discovered by the binary cataloger. The discovered file.Executable type has a []ImportedLibraries that's read from the file when discovered by syft. By mapping these imported libraries back to the package collection, syft is able to create relationships showing which packages are dependencies of other packages by just reading metadata from the ELF executable.

---------

Signed-off-by: Alex Goodman <wagoodman@users.noreply.github.com>
Signed-off-by: Brian Ebarb <ebarb.brian@sers.noreply.github.com>
Co-authored-by: Alex Goodman <wagoodman@users.noreply.github.com>

cmd/syft/internal/test/integration/package_binary_elf_relationships_test.go

@@ -0,0 +1,65 @@
+package integration
+
+import (
+	"github.com/anchore/syft/syft/artifact"
+	"github.com/anchore/syft/syft/source"
+	"github.com/stretchr/testify/require"
+	"testing"
+)
+
+func TestBinaryElfRelationships(t *testing.T) {
+	// node --> ["dependency of" nodes]
+	expectedGraph := map[string][]string{
+		"glibc": {
+			"libhello_world.so",
+			"syfttestfixture",
+		},
+		"libstdc++": {
+			"syfttestfixture",
+		},
+		"libhello_world.so": {
+			"syfttestfixture",
+		},
+	}
+
+	// run the test...
+	sbom, _ := catalogFixtureImage(t, "elf-test-fixtures", source.SquashedScope)
+
+	// get a mapping of package names to their IDs
+	nameToId := map[string]artifact.ID{}
+
+	recordPkgId := func(name string) {
+		pkgs := sbom.Artifacts.Packages.PackagesByName(name)
+		require.NotEmpty(t, pkgs, "expected package %q to be present in the SBOM", name)
+		for _, p := range pkgs {
+			nameToId[p.Name] = p.ID()
+		}
+	}
+	for name, depNames := range expectedGraph {
+		recordPkgId(name)
+		for _, depName := range depNames {
+			recordPkgId(depName)
+		}
+	}
+
+	for name, expectedDepNames := range expectedGraph {
+		pkgId := nameToId[name]
+		p := sbom.Artifacts.Packages.Package(pkgId)
+		require.NotNil(t, p, "expected package %q to be present in the SBOM", name)
+
+		rels := sbom.RelationshipsForPackage(*p, artifact.DependencyOfRelationship)
+		require.NotEmpty(t, rels, "expected package %q to have relationships", name)
+
+		toIds := map[artifact.ID]struct{}{}
+		for _, rel := range rels {
+			toIds[rel.To.ID()] = struct{}{}
+		}
+
+		for _, depName := range expectedDepNames {
+			depId := nameToId[depName]
+			_, exists := toIds[depId]
+			require.True(t, exists, "expected package %q to have a relationship to %q", name, depName)
+		}
+	}
+
+}

cmd/syft/internal/test/integration/test-fixtures/elf-test-fixtures

@@ -0,0 +1 @@
+../../../../../../syft/pkg/cataloger/binary/test-fixtures/elf-test-fixtures

cmd/syft/internal/test/integration/utils_test.go

@@ -32,7 +32,6 @@ func catalogFixtureImageWithConfig(t *testing.T, fixtureImageName string, cfg *s
 	cfg.CatalogerSelection = cfg.CatalogerSelection.WithDefaults(pkgcataloging.ImageTag)
 
 	// get the fixture image tar file
-	imagetest.GetFixtureImage(t, "docker-archive", fixtureImageName)
 	tarPath := imagetest.GetFixtureImageTarPath(t, fixtureImageName)
 
 	// get the source to build an SBOM against